TWI472570B - Thermoplastic resin composition and its molded article - Google Patents

Description

Thermoplastic resin composition and molded article thereof

The present invention relates to a thermoplastic resin composition excellent in impact resistance, durability due to heat retention (hereinafter also referred to as thermal stability), and further excellent moldability, and low environmental load, and a molded article formed therefrom .

The conventional molding material is a polyethylene resin, a polypropylene resin, a nylon resin, a polyester resin, an ABS resin, a polycarbonate resin, or a polyacetal resin, which is equal to all ranges. After the use of the product, due to burial or incineration, the semi-permanent residue in the land or the generation of carbon dioxide during incineration imposes a large load on the global environment. In recent years, the increase in the concentration of carbon dioxide in the atmosphere, which is one of the greenhouse gases, has been cited as the main cause of global warming, and the chance of suppressing carbon dioxide emissions in the earth is increased.

From the point of view of such environmental protection, we are working on the replacement of fossil resource materials that are used in the use of biomass. Even in the molding materials, attention is paid to plant-derived resins which can reduce the amount of fossil resources used and suppress the amount of carbon dioxide emissions. In the case of the resin of the plant, the aliphatic polyester resin of the polylactic acid resin is mainly represented by the resin, but the mechanical strength or heat resistance (heat distortion temperature) of the molded article is lowered as compared with the existing petroleum resin. The thermal stability of the polyester is also reduced, and the application range of the aliphatic polyester including polylactic acid can be narrowed. Moreover, the thermal stability due to the use of the aliphatic polyester resin is lowered, and it is difficult to obtain stable molding processing conditions, in addition to the influence on the flow characteristics of the resin, and also on the molding method or the size of the molding machine. Waiting for a big constraint. The characteristics of these aliphatic polyester resins are difficult to maintain stable physical properties, and mass production during market development is difficult, and it will become a major obstacle when it is promoted as a general-purpose resin in the future.

In order to improve the problem of the above-mentioned aliphatic polyester resin, various improvement studies have been carried out, and in the improvement method, a method of adding a polymer alloy or a modifier to the above-mentioned existing resin is being actively carried out.

Patent Document 1 discloses that a phosphate-based compound is added to an alloy of a rubber-reinforced styrene resin and a polycarbonate resin or a polyester resin to improve mechanical strength or thermal stability, and thermal stability of the polycarbonate resin is also described. However, there is no description about the thermal stability technique of the polyester resin, and the improvement of the thermal stability of the alloy of the rubber-reinforced styrene resin and the polyester resin needs to be further improved.

Further, in Patent Document 2, it is disclosed that a rubber-reinforced styrene-based resin or an acrylic resin is alloyed in an aliphatic polyester resin, and by further adding a dicarboxylic acid anhydride, both mechanical strength and heat resistance can be improved. However, research on thermal stability is insufficient and further improvement is needed. Further, it is described that the use of maleic anhydride or succinic anhydride is preferably used as the dicarboxylic anhydride, but in the case of compounding of the aliphatic polyester resin and the rubber-reinforced styrene resin and the acrylic resin. Or after the forming process, it produces a pungent odor. When considering the impact on the human body during production, it is safe. There is a problem with hygiene.

Prior technical literature Patent literature

Patent Document 1 JP-A-2007-254507

Patent Document 2, JP-A-2007-191688

Summary of invention

The invention is based on safety. It is a problem to provide a thermoplastic resin composition of an aliphatic polyester resin which is excellent in mechanical properties and thermal stability, which is excellent in heat resistance, and a molded article thereof.

As a result of intensive research to solve the above problems, the present inventors have found that by blending a styrene-based resin (A), a graft copolymer (B), and an aliphatic polyester resin (C), The thermoplastic resin composition composed of phosphoric acid and/or sodium dihydrogen phosphate (D) can solve the above problems.

That is, the present invention is constituted by the following (1) to (11).

(1) A thermoplastic resin composition comprising a phosphoric acid and/or sodium dihydrogen phosphate in a resin composition comprising a styrene resin (A), a graft copolymer (B) and an aliphatic polyester resin Formed by (D);

(2) The thermoplastic resin composition according to (1), wherein the resin composition further comprises an acrylic resin (E);

(3) The thermoplastic resin composition according to (1) or (2), wherein the aliphatic polyester resin (C) is polylactic acid;

(4) The thermoplastic resin composition according to any one of (1) to (3), wherein the polymer composition comprises 0.01 to 5 parts by weight of phosphoric acid and/or sodium dihydrogen phosphate with respect to 100 parts by weight of the above resin composition. (D);

(5) The thermoplastic resin composition according to any one of (1) to (4), wherein the styrene resin (A) is contained in an amount of 10 to 80 parts by weight based on 100 parts by weight of the resin composition. 5 to 70 parts by weight of graft Copolymer (B), 1 to 85 parts by weight of the aliphatic polyester resin (C), and 0 to 30 parts by weight of the acrylic resin (E);

(6) The thermoplastic resin composition according to any one of (1) to (5) wherein the styrene resin (A) is formed by polymerizing at least an aromatic vinyl monomer (a1);

(7) The thermoplastic resin composition according to any one of (1) to (6) wherein the graft copolymer (B) is graft-polymerized in the rubbery polymer (r) and contains at least an unsaturated carboxylic acid Forming a monomer component of the alkyl ester monomer (b1);

(A) The thermoplastic resin composition according to any one of (2) to (7), wherein the acrylic resin (E) is a polymethyl methacrylate resin;

(9) A method for producing a thermoplastic resin composition according to any one of (1) to (8), which is characterized in that the aliphatic polyester resin (C) is melt-kneaded. After the other components, the aliphatic polyester resin (C) is added and further melt-kneaded.

(10) A molded article obtained by molding the thermoplastic resin composition according to any one of (1) to (8);

(11) A sheet formed by molding the thermoplastic resin composition according to any one of (1) to (8).

According to the present invention, it is possible to obtain a thermoplastic resin composition excellent in mechanical properties, thermal stability, and further moldability, which are excellent in safety and hygiene, and a molded article thereof.

Form for implementing the invention

Hereinafter, the thermoplastic resin composition of the present invention will be specifically described.

The thermoplastic resin composition of the present invention is characterized in that a phosphoric acid and/or phosphoric acid is blended in a resin composition comprising a styrene resin (A), a graft copolymer (B) and an aliphatic polyester resin (C). Sodium dihydrogen (D).

The styrene resin (A) used in the present invention means styrene as a starting point, and α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, and the like. Ethyl styrene and an aromatic vinyl monomer (a1) such as p-t-butyl styrene are provided in conventional bulk polymerization, bulk suspension polymerization, and solution polymerization. In the case of precipitation polymerization or emulsion polymerization, it is preferred that the copolymerization contains at least an aromatic vinyl monomer (a1), and if necessary, other unsaturated alkyl carboxylate monomers ( A2) a vinyl cyanide monomer (a3) and a copolymer obtainable from the monomer mixture (a) of the other vinyl monomer (a4) copolymerized. Further, in the styrene resin (A), the graft copolymer obtained by graft-polymerizing the monomer component to the rubber polymer (r) is not contained.

Specific examples of the aromatic vinyl monomer (a1) constituting the styrene resin (A) are as described above, and styrene is α-methylstyrene or o-methylstyrene. And p-methylstyrene, o-ethylstyrene, p-ethylstyrene and p-tert-butylstyrene, among which styrene or α-methylstyrene is preferably used. One type or two or more types may be used.

The unsaturated carboxylic acid alkyl ester monomer (a2) constituting the styrene resin (A) is not particularly limited, but is preferably an acrylate having a carbon number of 1 to 6 or a substituted alkyl group. And/or methacrylate, as a specific example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate , (3) butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, ( 2-hydroxyethyl methacrylate, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and (meth)acrylic acid - 2,3,4,5-tetrahydroxypentyl ester, of which methyl methacrylate is most preferably used. One type or two or more types may be used.

The vinyl cyanide monomer (a3) constituting the styrene resin (A) is not particularly limited, and specific examples thereof include acrylonitrile, methacrylonitrile, and ethacrylonitrile. It is good to use acrylonitrile. One type or two or more types may be used.

The aromatic vinyl monomer (a1), the unsaturated carboxylic acid alkyl ester monomer (a2), and the vinyl cyanide can be used as the other vinyl monomer (a4) constituting the styrene resin (A). The monomer (a3) copolymerization is not particularly limited, and specific examples thereof include N-methylbutyleneimine, N-ethylbutyleneimine, and N-ring. a maleic acid imide monomer such as hexyl succinimide or N-phenyl maleimide; acrylic acid, methacrylic acid, maleic acid, maleic acid a vinyl monomer having a carboxyl group or a carboxylic anhydride group such as ethyl ester, maleic anhydride, citric acid or itaconic acid; 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4 -hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2 a vinyl monomer having a hydroxyl group such as pentene or 4,4-dihydroxy-2-butene; glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and itaconic acid Glycidyl ester, allyl epoxypropyl ether, styrene-p-epoxypropyl ether and p-epoxypropyl styrene Ethylene-based vinyl monomer; acrylamide, methacrylamide, N-methyl acrylamide, butoxymethyl decylamine, N-propyl methacrylamide, amine urethane, Propyl propyl acrylate, dimethylaminoethyl methacrylate, ethyl propyl methacrylate, aniline ethyl methacrylate, cyclohexylamine methacrylate, N-vinyldiethylamine, N-acetonitrile a vinyl monomer having an amine group and a derivative thereof, such as a vinylamine, an allylamine, a methylallylamine, an N-methylallylamine, a p-aminostyrene, or the like; 2-isopropenyl- Oxazoline, 2-vinyl- Oxazoline, 2-propenyl fluorenyl- Oxazoline and 2-styryl- Oxazoline One or two or more kinds of these may be used as the oxazolyl-based vinyl monomer.

The above monomer mixture (a) is blended in an amount of from 0 to 99 by weight based on 1 to 100% by weight of the aromatic vinyl monomer (a1) and from the unsaturated carboxylic acid alkyl ester monomer (a2). %, the vinyl cyanide monomer (a3) is 0 to 50% by weight, and the other vinyl monomer (a4) copolymerizable with the above is preferably 0 to 99% by weight, preferably an aromatic vinyl group. The monomer (a1) is 10 to 90% by weight, the unsaturated carboxylic acid alkyl ester monomer (a2) is 50 to 90% by weight, the vinyl cyanide monomer (a3) is 0 to 40% by weight, and The other vinyl monomer (a4) copolymerized with the above is 0 to 50% by weight, more preferably 15 to 80% by weight of the aromatic vinyl monomer (a1), and an unsaturated carboxylic acid alkyl ester monomer. (a2) is 60 to 80% by weight, the vinyl cyanide monomer (a3) is 0 to 30% by weight, and the other vinyl monomer (a4) copolymerizable with the above is 0 to 30% by weight.

The properties of the styrene-based resin (A) are not limited, but it is preferably 0.20 to 2.00 dl/g as measured by using a methyl ethyl ketone solvent at an organic viscosity [η] measured at 30 ° C. It is preferable to use a thermoplastic resin composition excellent in impact resistance and moldability, in the range of 0.25 to 1.50 dl/g, more preferably in the range of 0.25 to 1.0 dl/g.

The molecular weight of the styrene-based resin (A) is not limited, but it is preferably a range of weight average molecular weight of 10,000 to 400,000 as measured by gel permeation chromatography (GPC) by using a tetrahydrofuran solvent, more preferably In the range of 50,000 to 150,000, a thermoplastic resin composition excellent in impact resistance and moldability is obtained.

Specific examples of the styrene-based resin (A) used in the present invention include polystyrene, impact-resistant polystyrene, AS resin, AAS resin, AES resin, MAS resin, and MS resin. Further, one type or two or more types of the styrene resin (A) used in the present invention can be used, for example, by using a copolymerized methyl methacrylate as an unsaturated carboxylic acid alkyl ester monomer. The styrene-based resin of (a2) and the styrene-based resin which is not copolymerized with methyl methacrylate are excellent in impact resistance, heat resistance, surface appearance, and coloring property.

The graft copolymer (B) used in the present invention means that the monomer component is supplied to a conventional bulk polymerization, bulk suspension polymerization, solution polymerization, precipitation in the presence of a rubbery polymer (r). Polymerization or emulsion polymerization, obtained by graft-polymerizing a monomer component onto a rubbery polymer (r). Further, the graft copolymer (B) contains not only a graft copolymer which has been graft-polymerized with a monomer component on the rubbery polymer (r) but also a graft polymer (r) which is not grafted to the rubbery polymer (r). The monomer component of the polymer.

The rubbery polymer (r) is not particularly limited, but it is preferably one having a glass transition temperature of 0 ° C or less, and a diene rubber, an acrylic rubber, a vinyl rubber or the like is preferably used. In other words, it is a polybutadiene, a styrene-butadiene copolymer, a block copolymer of styrene-butadiene, an acrylonitrile-butadiene copolymer, a butyl acrylate-butadiene copolymer, Polyisoprene, butadiene-methyl methacrylate copolymer, butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-isoprene a diene copolymer, an ethylene-methyl acrylate copolymer, and the like. Among these rubbery polymers, polybutadiene, styrene-butadiene copolymer, styrene-butadiene block copolymer and propylene are preferably used from the viewpoint of impact resistance. As the nitrile-butadiene copolymer, one type or a mixture of two or more types can be used.

The weight average particle diameter of the rubbery polymer (r) is not particularly limited, but is preferably from 0.05 to 1.0 μm, particularly preferably from 0.1 to 0.5 μm. By making the weight average particle diameter of the rubbery polymer into the range of 0.05 μm to 1.0 μm, excellent impact resistance can be found. In addition, one or two or more kinds of rubbery polymers may be used. From the viewpoint of impact resistance and fluidity, it is preferred to use two or more kinds of rubbery polymer bodies having different weight average particle diameters, for example, combined weight. A rubber polymer having a small average particle diameter and a rubber polymer having a large weight average particle diameter may be a so-called bimodal rubber.

Further, the weight average particle diameter of the rubbery polymer (r) can be obtained by the alginic acid described in "Rubber Age, Vol. 88, p. 484-490, (1960), E. Schmidt, PH Biddison". The sodium method, that is, the ratio of the weight of the polybutadiene which is emulsified by the concentration of sodium alginate, the ratio of the weight of the whipped cream The cumulative weight fraction of the sodium alginate concentration was measured by a method of obtaining a particle size having a cumulative weight fraction of 50%.

The colloidal content of the rubbery polymer (r) is not particularly limited, but is preferably from 40 to 99% by weight, more preferably from 60 to 95% by weight, from the viewpoint of impact resistance and heat resistance. Preferably, it is 70 to 90% by weight. Here, the colloid content rate can be measured by a method of obtaining the ratio of insoluble components by using toluene at room temperature for 24 hours.

The graft copolymer (B) is preferably a graft polymerization monomer component in the presence of the rubbery polymer (r) of preferably 10 to 80% by weight, more preferably 30 to 70% by weight. %, more preferably 30 to 70% by weight. The proportion of the rubbery polymer is smaller than the above range, and is larger than the aforementioned range, and the punching strength or the surface appearance is lowered.

The monomer component constituting the graft component of the graft copolymer (B) preferably contains at least an unsaturated carboxylic acid alkyl ester monomer (b1), and if necessary, an aromatic vinyl monomer (b2), A vinyl cyanide monomer (b3), a monomer mixture (b) which is copolymerizable with the other vinyl monomer (b4).

The unsaturated carboxylic acid alkyl ester monomer (b1) constituting the graft copolymer (B) is preferably an acrylate having a carbon number of 1 to 6 or a substituted alkyl group, although it is not particularly limited. And / or methacrylate. Specific examples are methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylic acid. Butyl ester, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, chloromethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, 2-hydroxyl (meth)acrylate Ethyl ester, 3-hydroxypropyl (meth)acrylate, (methyl) 2,3,4,5,6-pentahydroxyhexyl acrylate and 2,3,4,5-tetrahydroxypentyl (meth)acrylate, etc., of which methyl methacrylate is most preferably used. One type or two or more types may be used.

The aromatic vinyl monomer (b2) constituting the graft copolymer (B) is not particularly limited, and specific examples are styrene, and α-methylstyrene and o-methylbenzene are exemplified. Ethylene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene and p-tert-butylstyrene, among which styrene and α-methylstyrene are preferably used. One type or two or more types may be used.

The vinyl cyanide monomer (b3) constituting the graft copolymer (B) is not particularly limited, and specific examples thereof include acrylonitrile, methacrylonitrile, and ethacrylonitrile. It is good to use acrylonitrile. One type or two or more types may be used.

The other vinyl monomer (b4) constituting the graft copolymer (B) is an unsaturated vinyl carboxylate monomer (b1), an aromatic vinyl monomer (b2), or vinyl cyanide. The monomer (b3) copolymerization is not particularly limited, and specific examples thereof include N-methyl maleimide, N-ethyl maleimide, and N-ring. a maleic acid imide monomer such as hexyl succinimide or N-phenyl maleimide; acrylic acid, methacrylic acid, maleic acid, maleic acid a vinyl monomer having a carboxyl group or a carboxylic anhydride group such as ethyl ester, maleic anhydride, citric acid or itaconic acid; 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4 -hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2 a vinyl monomer having a hydroxyl group such as pentene or 4,4-dihydroxy-2-butene; glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and itaconic acid Glycidyl ester, allyl epoxypropyl ether, styrene-p-epoxypropyl ether and p-epoxypropyl styrene Vinyl amide, acrylamide, methacrylamide, N-methyl acrylamide, butoxy methacrylamide, N-propyl methacrylamide, amine acrylate, acrylic acid Ethylamine ethyl ester, dimethylaminoethyl methacrylate, ethyl propyl methacrylate, aniline ethyl methacrylate, cyclohexylamine methacrylate, N-ethylenediethylamine, N-ethene ethylene a vinyl monomer having an amine group and a derivative thereof, such as an amine, an allylamine, a methylallylamine, an N-methylallylamine, a p-aminostyrene, or the like; 2-isopropenyl- Oxazoline, 2-vinyl- Oxazoline, 2-propenyl fluorenyl- Oxazoline and 2-styryl- Oxazoline One or two or more kinds of these may be used as the oxazolyl-based vinyl monomer.

The composition ratio of the monomer mixture (b) is preferably 20 to 90% by weight, more preferably 30 to 80% by weight, based on the unsaturated carboxylic acid alkyl ester monomer (b1); the aromatic vinyl monomer (b2) It is preferably 0 to 70% by weight, more preferably 0 to 50% by weight; the vinyl cyanide monomer (b3) is preferably 0 to 50% by weight, more preferably 0 to 30% by weight; The other vinyl monomer (b4) copolymerized is preferably from 0 to 70% by weight, more preferably from 0 to 50% by weight.

As described above, the graft copolymer (B) is a non-grafted polymer in addition to a graft copolymer having a structure in which a monomer component is grafted onto a rubbery polymer (r). The graft ratio of the graft copolymer (B) is not particularly limited, but an excellent resin composition is obtained in order to balance the impact resistance and gloss, and is preferably from 10 to 100% by weight, particularly preferably from 20 to 80% by weight. The range of %. Among them, the graft ratio is a value calculated by the following formula.

Graft ratio (%) = [<amount of ethylene-based copolymer graft-polymerized to rubbery polymer body>/<rubber content of graft copolymer>] × 100

The characteristics of the ungrafted polymer contained in the graft copolymer (B) are not particularly limited, but the intrinsic viscosity [η] (measured at 30 ° C) of the methyl ethyl ketone soluble component is 0.10 to 1.00. The range of dl/g, particularly 0.20 to 0.80 dl/g, is preferable because a resin composition having excellent impact resistance is obtained.

As described above, the graft copolymer (B) can be obtained by a conventional polymerization method. For example, a method in which a mixture of a monomer and a chain transfer agent and a solution of a radical generator dissolved in an emulsifier are continuously supplied to a polymerization vessel to carry out emulsion polymerization in the presence of a rubber polymer latex is obtained.

The aliphatic polyester resin (C) to be used in the present invention is a polymer which is a constituent component mainly composed of an aliphatic hydroxycarboxylic acid, and a polymerization of a constituent component mainly composed of an aliphatic polycarboxylic acid and an aliphatic polyhydric alcohol. Things and so on. Specifically, the polymer which is a constituent component mainly composed of an aliphatic hydroxycarboxylic acid is exemplified by polyglycolic acid, polylactic acid, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, poly 4 - hydroxyvaleric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, etc.; a polymer which is a constituent component mainly composed of an aliphatic polycarboxylic acid and an aliphatic polyhydric alcohol, and is exemplified by polyvinyl adipate and poly Vinyl succinate, polybutylene adipate or polybutylene succinate. These aliphatic polyester resins may be used singly or in combination of two or more. Among these aliphatic polyester resins, a polymer containing a constituent component mainly composed of a hydroxycarboxylic acid is preferably used, and polylactic acid is particularly preferably used.

In the case of polylactic acid, although it is a polymer mainly composed of L-lactic acid and/or D-lactic acid, it does not impair the object of the present invention. It may also contain other copolymerized components other than lactic acid. Examples of other units of the copolymerization component are polycarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones and the like. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, and hexamethylene can be used. Acid, azelaic acid, sebacic acid, dodecanedioic acid, fumaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalene Polycarboxylic acids such as dicarboxylic acid, 5-sodium sulfoisophthalate, 5-tetrabutylphosphonium sulfoisophthalate; ethylene glycol, propylene glycol, dibutyl Alcohol, pentanediol, hexanediol, octanediol, decanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerol, trimethylolpropane, neopentyl alcohol , bisphenol A, an aromatic polyol which reacts ethylene oxide with bisphenol, a polyhydric alcohol such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol or polytetramethylene glycol. ; hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, hydroxybenzoic acid; glycolide, ε-caprolactone glycolide And lactones such as ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, and δ-valerolactone. These copolymerization components may be used alone or in combination of two or more.

From the viewpoint of heat resistance, the polylactic acid preferably has a high optical purity of the lactic acid component, and preferably contains 80 mol% or more of L body or D body in the total lactic acid component, more preferably 90 mol. More than %, particularly preferably 95% or more.

Further, from the viewpoint of heat resistance and moldability, it is also preferable to use a polylactic acid stereo compound. The method for forming the polylactic acid stereo complex is exemplified by mixing by melt mixing or solution kneading. The L body is 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more of poly-L-lactic acid, and the D body is 90 mol% or more, preferably 95 mol%. More preferably, the method of poly-D-lactic acid of 98 mol% or more is more preferable. Further, as another method, a method in which poly-L-lactic acid and poly-D-lactic acid are used as a block copolymer is also mentioned, and from the viewpoint that a polylactic acid stereo compound can be easily formed, it is preferred that A method in which poly-L-lactic acid and poly-D-lactic acid are block copolymers.

As a method for producing the aliphatic polyester resin (C), a known polymerization method can be used, and in particular, for the polylactic acid, a direct polymerization method starting from lactic acid, a ring-opening polymerization method via lactide, or the like can be used.

The molecular weight or molecular weight distribution of the aliphatic polyester resin (C) is not particularly limited as long as it can be subjected to a forming process, but the weight average molecular weight is preferably 10,000 or more, more preferably 40,000 or more, and particularly preferably More than 80,000. The weight average molecular weight refers to a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

The melting point of the aliphatic polyester resin (C) is not particularly limited, but is preferably 90 ° C or higher, more preferably 150 ° C or higher.

Further, in the present invention, the melt viscosity ratio of the styrene resin (A) to the aliphatic polyester resin (C) is obtained from the viewpoint of obtaining a resin composition excellent in heat resistance ((A)/(C) It is preferably in the range of 0.1 to 10. For the melt viscosity, a capillary electrophoresis chart measuring device (capillary electrophoresis model No. 1C manufactured by Toyo Seiki Seisakusho Co., Ltd., an orifice length of 20 mm, an orifice diameter of 1 mm) was used, and the shear rate was 220 ° C. It is a measured value of 1000 s ^-1 .

In the present invention, in addition to the above (A) to (C) as a resin composition, it is preferred to further blend the acrylic resin (E).

The acrylic resin (E) used in the present invention means a polymer or copolymer of a (meth)acrylic acid alkyl ester monomer, a styrene resin (A), a graft copolymer (B), and a fat. A polymer other than the group polyester resin (C). With the addition of the acrylic resin (E), the impact resistance can be improved.

Examples of the (meth)acrylic acid alkyl ester-based monomer include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and methacrylic acid ring. Hexyl ester, hydroxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate, amine acrylate, propylamine acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate , glycidyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyl acrylate, butylene glycol diacrylate, decanediol diacrylate, polyethylene glycol diacrylate, 2-(hydroxymethyl) Methyl acrylate, ethyl 2-(hydroxymethyl)acrylate, methacrylic acid, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid Ethyl propyl acrylate, aniline ethyl methacrylate, cyclohexylamine methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, A Dicyclopentenyloxyethyl acrylate, dicyclopentenyl methacrylate, methyl propyl Pentamethylpiperidyl methacrylate, tetramethylpiperidine methacrylate, benzyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, polyethylene glycol II One type or two or more types may be used for the methacrylate or the like.

Further, a copolymer having a ring structural unit such as a lactone ring, maleic anhydride or glutaric anhydride in the main chain may be used.

In the acrylic resin (E) of the present invention, a polymethyl methacrylate resin containing a methyl methacrylate component as a main component is preferable, and a methyl methacrylate component of 70% or more is preferable. The unit is a polymethyl methacrylate resin, more preferably a polymethyl methacrylate (PMMA) resin.

Further, the molecular weight or the molecular weight distribution of the acrylic resin (E) is not particularly limited as long as it can be subjected to a molding process, but the weight average molecular weight is preferably from 1,000 to 450,000 from the viewpoint of moldability. Preferably, it is 10,000 to 200,000, more preferably 30,000 to 150,000. The weight average molecular weight refers to an average molecular weight in terms of polymethyl methacrylate (PMMA) measured by GPC using hexafluoroisopropanol as a solvent.

Further, from the viewpoint of heat resistance, the glass transition temperature of the acrylic resin (E) is preferably 60 ° C or higher, preferably 70 ° C or higher, more preferably 80 ° C or higher, and particularly preferably 90 ° C or higher. Good is above 100 °C. The upper limit is not particularly limited, but is preferably 150 ° C or less from the viewpoint of moldability. The glass transition temperature is a value obtained by measuring the glass transition temperature by a differential scanning calorimeter (DSC), which is a temperature at which the specific heat capacity in the glass transition temperature range changes to a half value.

When a polymethyl methacrylate resin is used as the acrylic resin (E), the syndiotacticity of the methacrylic resin is preferably 20% or more, preferably 30% or more, and more preferably 40% or more. The upper limit is not particularly limited, but is preferably 90% or less from the viewpoint of moldability. Further, from the viewpoint of heat resistance, the heterotacticity is preferably 50% or less, more preferably 40% or less, still more preferably 30% or less. Further, from the viewpoint of heat resistance, the isotacticity is preferably 20% or less, preferably 15% or less, more preferably 10% or less. The term "syndiotactic, heterodispensable, and homogenous" refers to the calculated methyl integral intensity ratio of a linear branch determined by ¹ H-NMR using a deuterated chloroform as a solvent. value.

As a method of producing the acrylic resin (E), a conventional polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization can be used.

The blending ratio of the resin composition in the present invention is not particularly limited, and in order to achieve the effects of the present invention, the styrene resin (A) is 10 to 80 in a total amount of 100 parts by weight of the resin composition. The parts by weight are preferably from 15 to 75 parts by weight, more preferably from 20 to 70 parts by weight, particularly preferably from 30 to 60 parts by weight, and the graft copolymer (B) is preferably from 5 to 70 parts by weight. It is preferably 5 to 65 parts by weight, more preferably 10 to 60 parts by weight, particularly preferably 10 to 50 parts by weight; and the aliphatic polyester resin (C) is preferably 1 to 85 parts by weight, preferably 5 to 80 parts by weight. The parts by weight are more preferably 5 to 70 parts by weight; the acrylic resin (E) is preferably 0 to 30 parts by weight, preferably 1 to 30 parts by weight, more preferably 2 to 20 parts by weight.

The thermoplastic resin composition of the present invention is characterized by containing phosphoric acid and/or sodium dihydrogen phosphate (D) in addition to the above resin component. Phosphoric acid and/or sodium dihydrogen phosphate (D) is used to prevent alkali decomposition of the aliphatic polyester resin (C) due to alkalinity of the graft copolymer (B) during its production process, and to improve the resin composition. Used for the purpose of thermal stability. And because of the tree The raw material blending or melt compounding of the fat composition, and the odor caused by the formation of the obtained resin composition is safe to the human body. From the viewpoint of hygiene, thermal stability of the resin composition, and the like, it is characterized by being superior to other neutralizing agents contained in conventional organic acids and the like.

In particular, when it is promoted to food appliances or toys, it is safe for the human body. When the hygienic requirements are more stringent, it is preferred to use sodium dihydrogen phosphate. Sodium dihydrogen phosphate itself has been widely used in the medical field or food supplements, and in addition to the safety of ingestion, it has been confirmed by the industry's self-regulatory group to prevent the health hazards caused by food appliances and the like. In the hygiene agreement meeting such as polyolefins, it was confirmed that it is suitable as a resin additive (registered on the positive list of additives).

The content of the phosphoric acid and/or sodium dihydrogen phosphate (D) in the thermoplastic resin composition of the present invention is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the total of the resin composition. 0.1 to 2 parts by weight, more preferably 0.1 to 0.5 parts by weight. When the content of the phosphoric acid and/or sodium dihydrogen phosphate (D) is less than 0.01 parts by weight, the effect of suppressing alkali decomposition of the aliphatic polyester resin (C) is not sufficiently exerted, and the thermoplastic resin composition of the present invention is not lowered. In the initial stage, the impact resistance is improved, and the impact resistance is greatly reduced when the heat is retained. When the amount is more than 5 parts by weight, the foaming of the molded article or the surface appearance of the molded article is lowered.

In addition, if it is an acidic substance which can carry out alkaline neutralization of the graft copolymer (B), it is manufactured without impairing the characteristic of the phosphoric acid and / or sodium dihydrogen phosphate (D) of this invention. Security on the top. The health perspective does not have an impact and any of them can be used. Specifically, inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid; acetic acid, oxalic acid, and propylene glycol are mentioned. Acid, succinic acid, maleic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, citric acid, terephthalic acid, isophthalic acid, ortho-benzene Organic acids such as dicarboxylic acid, benzoic acid, trimellitic acid, pyromellitic acid, phenol, naphthalenedicarboxylic acid, diphenic acid, etc.; oxalic acid, malonic acid An acid anhydride of succinic acid, maleic acid, adipic acid, sebacic acid, sebacic acid, dodecanedioic acid, citric acid, phthalic acid, trimellitic acid, and pyromellitic acid. When the above-mentioned compounds other than phosphoric acid or sodium dihydrogen phosphate are used in combination, it is not necessary to use one type, and they may be used in combination.

In the present invention, from the viewpoint of improving heat resistance, it is preferred to further contain a nucleating agent. For the nucleating agent, a nucleating agent for a polymer to be used in general can be used without any particular limitation, and any of an inorganic nucleating agent and an organic nucleating agent can be used, and two or more kinds of them can be used singly or in combination.

Specific examples of inorganic nucleating agents include talc, kaolinite, montmorillonite, mica, synthetic mica, clay, zeolite, vermiculite, graphite, carbon black, zinc oxide, magnesium oxide, and oxidation. Calcium, titanium oxide, calcium sulfide, boron nitride, magnesium carbonate, calcium carbonate, barium sulfate, aluminum oxide, cerium oxide, metal salt of phenylphosphonate, etc.; from the viewpoint of improving the heat resistance, it is preferred It is talc, kaolinite, microcrystalline kaolinite and synthetic mica. These may be used alone or in combination of two or more. In order to improve the dispersibility in the composition, it is preferred to modify these inorganic nucleating agents with an organic substance.

The content of the inorganic nucleating agent is preferably from 0.01 to 100 parts by weight, preferably from 0.05 to 50 parts by weight, more preferably from 0.1 to 30 parts by weight, per 100 parts by weight of the aliphatic polyester resin (C).

Specific examples of the organic nucleating agent include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, bismuth benzoate, lithium terephthalate, sodium terephthalate, and terephthalic acid. Potassium formate, calcium oxalate, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octadecanoate, calcium octadecanoate, sodium stearate, Potassium stearate, lithium stearate, calcium stearate, magnesium stearate, barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium citrate, potassium citrate, zinc laurate, two An organic carboxylic acid metal salt such as aluminum benzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthoate or sodium cyclohexanoate; an organic sulfonate such as sodium p-toluenesulfonate or sodium sulfoisophthalate; a carboxylic acid decylamine such as decylamine stearate, decylamine dilaurate, decyl palmitate, decyl hydroxystearate, decyl succinate, tris(tridecylamine); Low density polyethylene, high density polyethylene, polypropylene, polyisopropene, polybutene, poly-4-methylpentene, poly-3-methylbut-1-ene, polyethylene naphthenic a polymer having a carboxyl group such as a polyethylene trialkyl decane or a high melting point polylactic acid; a sodium salt of an ethylene-acrylic acid or methacrylic acid copolymer; a sodium salt of a styrene-maleic anhydride copolymer; Sodium or potassium salt (ie, ionomer); benzylidene sorbitol and its derivatives; sodium-2,2'-methylenebis (4,6-di A phosphorus compound metal salt such as tributylphenyl phosphate or a 2,2-methylbis(4,6-di-t-butylphenyl) sodium or the like is preferable from the viewpoint of enhancing the heat resistance. It is an organic carboxylic acid metal salt and a carboxylic acid decylamine. These may be used alone or in combination of two or more.

The content of the organic nucleating agent is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 10 parts by weight, still more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the aliphatic polyester resin (C).

In the present invention, it is preferred to further contain a plasticizer from the viewpoint of improving heat resistance. In the case of a plasticizer, a plasticizer which is generally used as a polymer can be used without particular limitation, and examples thereof include a polyester plasticizer, a glycerin plasticizer, a polycarboxylic acid ester plasticizer, and a polyalkylene oxide. An alcohol-based plasticizer and an epoxy-based plasticizer may be used alone or in combination of two or more.

Specific examples of the polyester-based plasticizer include acid components such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, and dicarboxylic acid, and propylene glycol and 1, a hydroxycarboxylic acid such as a polyester or a polylactone formed of a diol component such as 3-butanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol or diethylene glycol The formed polyester or the like. These polyesters may be blocked by a monofunctional carboxylic acid or a monofunctional alcohol, or may be blocked by an epoxy compound or the like.

Specific examples of the glycerin-based plasticizer include glycerin monoacetate monolaurate, glycerin diethyl laurate, glycerol monoacetate monostearate, and C. Triol diethyl oleate monooleate and glycerol monoethyl citrate monochamoester.

Specific examples of the polycarboxylic acid-based plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, and dibenzyl phthalate. a phthalic acid ester such as butyl benzyl phthalate; a trimellitic acid ester such as tributyl trimellitate, trioctyl trimellitate or trihexyl trimellitate; diisononyl adipate; An adipic acid ester such as n-octyl decanoate; a citrate ester such as triethyl citrate or tributyl citrate; a bismuth sebacate such as di-2-ethylhexyl sebacate; Diacid esters; dibutyl sebacate; and sebacate such as di-2-ethylhexyl sebacate.

Specific examples of the polyalkylene glycol-based plasticizer include polyethylene glycol, polypropylene glycol, poly(ethylene oxide, propylene oxide) block and/or random copolymer, and polytetramethylene. A polyalkylene glycol such as an alcohol, a bisphenol-based ethylene oxide addition polymer, a bisphenol-based propylene oxide addition polymer, a bisphenol-based tetrahydrofuran addition polymer, or a terminal epoxy modification thereof a terminal blocking compound such as a compound, a terminal ester modifying compound, and a terminal ether modifying compound.

The epoxy plasticizer generally refers to an epoxy triglyceride formed from alkyl epoxy stearate and soybean oil, and in other aspects, such as mainly bisphenol A and epichlorohydrin ( Epichlorohydrin) is a raw material, that is, epoxy resin is used as a plasticizer.

Specific examples of other plasticizers include aliphatic polyalcohols such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, and triethylene glycol di-2-ethylbutyrate. Benzoate; fatty acid guanamine such as decylamine sulphate; aliphatic carboxylic acid ester such as butyl oleate; methyl acetylricinoleate, butyl ricinoleic acid butyl phthalate Isooxylates; pentaerythritol, various sorbitol, polyacrylates, polyoxyxides, and paraffin.

Further, in the case of the plasticizer which is preferably used in the present invention, at least one selected from the group consisting of a polyester-based plasticizer and a polyalkylene glycol-based plasticizer is particularly preferable.

The content of the plasticizer is preferably in the range of 0.01 to 30 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the aliphatic polyester resin (C). The scope.

In the present invention, although the nucleating agent and the plasticizer may be used singly, it is preferred to use them in combination.

In the present invention, it is more preferable to contain a filler other than the inorganic nucleating agent from the viewpoint of improving heat resistance. As the filler other than the inorganic nucleating agent, those which are generally used for reinforcing the thermoplastic resin, such as a fibrous form, a plate form, a granular form, or a powder form can be used. Specifically, it is glass fiber, asbestos fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, lanthanide whisker, ash stone, sepiolite, Asbestos, slag fiber, xonotlite, ellestadite, gypsum fiber, vermiculite fiber, vermiculite. Inorganic fibrous fillers such as alumina fibers, zirconia fibers, boron nitride fibers, tantalum nitride fibers, and boron fibers; polyester fibers, nylon fibers, acrylic fibers, regenerated cellulose fibers, acetate fibers, and foreign fibers Hemp, ramie, cotton, jute, hemp, sisal, linen, linen, silk, Manila hemp, sugar cane, wood pulp, waste paper, old Organic fibrous fillers such as paper and wool; glass flakes, graphite, metal foil, ceramic beads, sericite, bentonite, dolomite, micronized niobate, feldspar powder, potassium titanate, shirasu balloon, A plate-like or granular filler of aluminum citrate, cerium oxide, gypsum, novaculitic chert, dawsonite, white clay, and the like. Among these fillers, inorganic fibrous fillers are preferred, and glass fibers and apatite are particularly preferred. Further, the use of the organic fibrous filler is also preferable, and from the viewpoint of utilizing the biodegradability of the aliphatic polyester resin (C), it is more preferably a natural fiber or a recycled fiber. Further, the aspect ratio (average fiber length / average fiber diameter) of the fibrous filler to be blended is preferably 5 or more, preferably 10 or more, more preferably 20 or more.

Further, the above-mentioned filler is covered or bundled with a thermoplastic resin such as an ethylene/vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or a coupling agent such as an amino decane or an epoxy decane. Can be processed.

The content of the filler is preferably from 0.1 to 200 parts by weight, more preferably from 0.5 to 100 parts by weight, per 100 parts by weight of the aliphatic polyester resin (C).

In the present invention, from the viewpoint of improving heat resistance and durability due to hydrolysis inhibition of the aliphatic polyester resin (C), it is preferred to further contain a carboxyl reactive terminal blocking agent. The carboxyl group-reactive terminal blocking agent is not particularly limited as long as it is a compound capable of blocking the carboxyl terminal group of the polymer, and a blocking agent which is used as a carboxyl group terminal of the polymer can be used. In the present invention, the related carboxy reactive terminal blocking agent not only blocks the end of the aliphatic polyester resin (C), but also blocks the acidity of lactic acid or formic acid formed by thermal decomposition or hydrolysis from a natural organic filler. a carboxyl group of a low molecular compound. Further, it is more preferred that the terminal blocking agent block the hydroxyl terminal of the acidic low molecular compound due to thermal decomposition.

In terms of the carboxy reactive terminal blocking agent, it is preferred to use an epoxy compound, Oxazoline compound, A compound of at least one of a compound, a carbodiimide compound, and an isocyanate compound is preferably an epoxy compound and/or a carbodiimide compound.

The content of the carboxyl reactive terminal blocking agent is preferably in the range of 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, per 100 parts by weight of the aliphatic polyester resin (C).

Although the timing of addition of the carboxyl reactive terminal blocking agent is not particularly limited, it not only improves heat resistance but also improves mechanical properties or thermal stability. From the viewpoint, it is preferred to melt-knead with the aliphatic polyester resin (C) in advance, and then knead it with others.

In the present invention, a stabilizer (antioxidant, ultraviolet absorber, weathering agent, etc.), a lubricant, a release agent, a flame retardant, a dye containing a dye or a pigment may be added in a range not impairing the object of the present invention. Agent, antistatic agent, foaming agent, etc.

In the present invention, other thermoplastic resins (for example, polyamidene resin, polyphenylene sulfide resin, polyetheretherketone resin, aliphatic polyester) may be further contained in the range which does not impair the object of the present invention. Polyester resin other than resin (C), polyfluorene resin, polyether oxime resin, aromatic and aliphatic polycarbonate resin, polyarylate resin, polyphenylene oxide resin, polyacetal resin , polyimine resin, polyether sulfimide resin, aromatic and aliphatic polyketone resin, fluororesin, polyvinyl chloride resin, polyvinylidene chloride, vinyl ester resin, cellulose acetate resin, polyethylene At least one of an alcohol resin or the like or a thermosetting resin (for example, a phenol resin, a melamine resin, a polyester resin, a polyoxymethylene resin, an epoxy resin, or the like). By blending these resins, a molded article having excellent characteristics can be obtained.

The foregoing various additives blended in the thermoplastic resin composition of the present invention may be blended at any stage of the production of the thermoplastic resin composition of the present invention, for example, a method of simultaneously adding a resin component, or pre-melting. A method in which a resin of at least two components is kneaded and then added.

The method for producing the thermoplastic resin composition of the present invention is exemplified by premixing a resin component and phosphoric acid and/or sodium dihydrogen phosphate (D), and After the nucleating agent, plasticizer, filler, and other additives as needed, the method of uniformly kneading and kneading in a uniaxial or biaxial extruder above the melting point of the resin component, or removing the solvent after mixing in the solution Method and so on. Further, when the thermoplastic resin composition is produced by mixing the above components, the aliphatic polyester resin (C) is alkali-decomposed depending on the components to be mixed, and in order to suppress alkali decomposition of the aliphatic polyester resin (C), It is preferred to prepare a pellet in which the graft copolymer (B), phosphoric acid and/or sodium dihydrogen phosphate (D) have been previously kneaded.

In addition, when a thermoplastic resin composition is produced for the purpose of molding into an extruded product such as a sheet, it is preferred to add an aliphatic polyester resin after melt-kneading a component other than the aliphatic polyester resin (C). (C) The thermoplastic resin composition of the present invention is produced by further melt-kneading. The method is described in detail, and a resin component other than the aliphatic polyester resin (C) and phosphoric acid and/or sodium dihydrogen phosphate are supplied from the upper supply port (main raw material supply side) of the twin-screw extruder. D), and the aforementioned nucleating agent, plasticizer, filler, and other additives, and then supply the aliphatic polyester from the side supply port (the auxiliary material supply side) existing near the center of the full length of the barrel of the twin-screw extruder The resin (C) is further melt-kneaded to obtain a thermoplastic resin composition. In the molded article such as a sheet, when the surface appearance is important, by this method, it is possible to reduce the occurrence of a material which is a cause of damage to the surface.

The thermoplastic resin composition of the present invention can be formed by any conventional method such as injection molding, extrusion molding, inflation molding, and air blowing molding, and can be widely used as a molded article. 4. The so-called molded product refers to film, sheet, fiber. Cloth, non-woven fabric, injection molded product, Extrusion products, vacuum pressure molded products, blow molded products, or composites with other materials, etc., useful as automotive materials, motors. Materials for electronic equipment, agricultural materials, horticultural materials, fishery materials, civil engineering. Use of construction materials, stationery, medical supplies, toilet seat cushions, and groceries.

Example

The present invention will be described in more detail and in detail, and the examples are given below, but the examples are not intended to limit the invention. Furthermore, unless otherwise indicated, "%" means % by weight.

The evaluation methods performed in the examples are explained below.

(1) Intrinsic viscosity [η] of a component soluble in methyl ethyl ketone of a styrene resin (A) and a graft copolymer (B)

The measurement sample was calculated by measuring the viscosity at 30 ° C using 0.2 g/100 ml of methyl ethyl ketone as a solvent and 0.4 g / 100 ml of methyl ethyl ketone as a solvent using a Ubbelohde viscometer.

(2) Weight average particle diameter of the rubbery polymer (r) in the graft copolymer (B)

Using the sodium alginate method described in "Rubber Age, Vol. 88, p. 484-490, (1960), E. Schmidt, PH Biddison", that is, the condensed polycondensate using the concentration of sodium alginate The diene particle size was different, and the particle diameter of the cumulative weight fraction of 50% was determined from the cumulative weight ratio of the weight ratio of the creamed to the sodium alginate concentration.

(3) Graft ratio of graft copolymer (B)

Adding 100 ml of acetone to a predetermined amount (m; 1 g) of the rubber-containing graft copolymer (A) which has been vacuum-dried at a temperature of 80 ° C for 4 hours, After refluxing for 3 hours in a hot water bath at a temperature of 70 ° C, the solution was centrifuged at 8800 rpm (10000 G) for 40 minutes, and then the insoluble matter was filtered, and the insoluble component was vacuum dried at 80 ° C for 4 hours. Weight (n). The graft ratio is calculated by the following formula. Wherein L is the rubber content of the rubber-containing graft copolymer.

Graft ratio (%) = {[(n) - (m) × L] / [(m) × L]} × 100

(4) Weight average molecular weight

The weight average molecular weight of the polylactic acid which is the aliphatic polyester resin (C) is a GPC apparatus manufactured by Water Co., Ltd., and a differential refractometer is used as a detector (Water 2414), and MIXED manufactured by Polymer Laboratories Co., Ltd. -B (2 pieces) as a column, the fraction is hexafluoroisopropanol, the flow rate is 1 ml / min, and the weight of polymethyl methacrylate (PMMA) measured by the column temperature of 40 ° C The average molecular weight is measured, and the weight average molecular weight of the methyl ethyl ketone-soluble component of the styrene resin (A) and the graft copolymer (B) is in addition to the use of tetrahydrofuran as a fraction. The same device for the determination of polylactic acid. The conditions were measured.

(5) Charpy impact strength

The measurement was carried out in accordance with ISO179. The molding conditions of the test piece were a cylinder temperature of 220 ° C and a mold temperature of 60 ° C.

(6) MFR measurement

The measurement was carried out in accordance with ISO 1133 (measured at a temperature of 220 ° C under a 98 N load).

(7) Heat resistance evaluation (heat distortion temperature measurement)

The heat distortion temperature was measured in accordance with ISO 75-1, 2. The molding conditions of the test piece were a cylinder temperature of 220 ° C and a mold temperature of 60 ° C.

(8) Thermal retention of Charpy impact strength

The test piece was molded under the conditions of a cylinder temperature of 220 ° C for 10 minutes, and was injected into a mold adjusted to a mold temperature of 60 ° C to obtain a test piece. Subsequent operations are performed in accordance with ISO 179.

(9) Thermal retention MFR determination

Except for the conditions of the MFR measurement of the above (6), the measurement was repeated for 10 minutes in the cylinder.

(10) Thermal stability assessment

With Charpy impact strength and MFR, the durability due to heat retention was evaluated from the initial values and the values of heat retention (I) and (H) calculated by the following formula. That is, the smaller the rate of change, the better the stability.

Rate of change of Charpy impact strength (%) = ((I) - (H)) / (I) × 100

Rate of change of MFR (%) = ((H) - (I)) / (I) × 100

(11) Evaluation of the sheet

The thermoplastic resin composition pellet was sandwiched by a metal mold, and the melt which had been heated and pressurized at 220 ° C for 3 minutes by a press molding machine was stretched to obtain a sheet having a length and width of 100 mm × 300 mm and a thickness of 0.3 to 0.5 μm. material. It is visually evaluated for appearance, and if there is no object in the area, it is represented by +, and if it is, it is represented by -.

(12) Security. Sanitary surface confirmation

It was confirmed whether there was a pungent odor at the time of melt compounding or the injection of the obtained pellets.

Hereinafter, the raw materials used in the examples, the method for producing the same, and the like are shown.

[Styrene resin (A)]

<Method of Manufacturing (A)-1>

Adding 0.05 parts by weight of methyl methacrylate/propylene amide copolymer dissolved in a stainless steel autoclave with a 20 L capacity, baffle and Paffler and Pfaudler type agitating blades (In Japanese Patent Publication No. 45-24151), a solution of 165 parts by weight of ion-exchanged water was stirred at 400 rpm, and the inside of the system was replaced with nitrogen. Next, the following mixture was stirred and added to the reaction system, and the temperature was raised to 60 ° C to start polymerization.

After the reaction temperature was raised to 65 ° C for 30 minutes, the temperature was raised to 100 ° C over a period of 120 minutes. Thereafter, the reaction system is cooled, the polymer is separated, washed, and dried according to a usual method to obtain a bead polymer. The methyl ketone-soluble component of the obtained styrene resin had an intrinsic viscosity of 0.53 dl/g and a weight average molecular weight of 134,000.

<Method of Manufacturing (A)-2>

Suspension polymerization was carried out in the same manner as in the above (A)-1 except that 0.31 part by weight of 2,2'-azobisisobutyronitrile was changed to 0.15 part by weight. The methyl ketone-soluble component of the obtained styrene resin had an intrinsic viscosity of 0.89 dl/g and a weight average molecular weight of 351,000.

<Method of Manufacturing (A)-3>

Suspension polymerization was carried out in the same manner as in the above (A)-1 except that the monomer component was changed to 70 parts by weight of methyl methacrylate, 25 parts by weight of styrene, and 5 parts by weight of acrylonitrile. The methyl ketone-soluble component of the obtained styrene resin had an intrinsic viscosity of 0.35 dl/g and a weight average molecular weight of 105,000.

<Method of Manufacturing (A)-4>

The monomer component was changed to 67 parts by weight of methyl methacrylate, 20 parts by weight of styrene, 13 parts by weight of acrylonitrile, and 0.33 parts by weight of third-dodecylmercaptan to 0.35 parts by weight. The suspension polymerization was carried out in the same manner as in the above (A)-1 except that 0.31 part by weight of 2,2'-azobisisobutyronitrile was changed to 0.4 part by weight. The methyl ketone-soluble component of the obtained styrene resin had an intrinsic viscosity of 0.46 dl/g and a weight average molecular weight of 114,000.

[Graft Copolymer (B)]

<Method of Manufacturing (B)-1>

(Nipol LX111A2" manufactured by Japan ZEON Co., Ltd.) (solid content conversion)

The above material was placed in a polymerization vessel and stirred while raising the temperature to 65 °C. When the internal temperature reached 65 ° C, the polymerization started, and 35 parts by weight of styrene, 15 parts by weight of acrylonitrile, and 0.3 parts by weight of the third-dodecylmercaptan were continuously added dropwise over 5 hours, and 0.25 weight was contained. An aqueous solution of cumene hydroperoxide, 2.5 parts by weight of potassium oleate, and 25 parts by weight of pure water was continuously added dropwise over 7 hours to terminate the reaction. The graft copolymer latex obtained by solidification with sulfuric acid is neutralized with sodium ketone, washed, filtered, and dried to obtain a powder. The graft copolymer obtained had a graft ratio of 50%, and the component soluble in methyl ethyl ketone had an intrinsic viscosity of 0.30 dl/g and a weight average molecular weight of 83,000.

<B-2>

Emulsification polymerization was carried out in the same manner as in the above (B)-1 except that the monomer component was changed to 35 parts by weight of methyl methacrylate, 12.5 parts by weight of styrene, and 2.5 parts by weight of acrylonitrile. The graft copolymer obtained had a graft ratio of 45%, and the component soluble in methyl ethyl ketone had an intrinsic viscosity of 0.28 dl/g and a weight average molecular weight of 75,000.

[Aliphatic Polyester Resin (C)] <C-1> polylactic acid

Polylactic acid manufactured by NatureWorks Co., Ltd. (poly-L-lactic acid having a weight average molecular weight of 200,000, a D-lactic acid unit of 1%, and a melting point of 175 ° C).

[Phosphoric acid and / or sodium dihydrogen phosphate (D)]

<(D)-1>phosphoric acid (0.5 mol/L aqueous solution) (manufactured by Kanto Chemical Co., Ltd.)

<(D)-2> anhydrous sodium dihydrogen phosphate (made by Taiping Chemical Industry Co., Ltd.)

[Acrylic resin (E)]

<(E)-1> Polymethyl methacrylate resin (Sumitomo Chemical Co., Ltd. "SUMIPEX MH")

[Dicarboxylic anhydride (F)]

In Comparative Examples 1 to 5, the following dicarboxylic acid anhydride (F) was used in place of phosphoric acid and/or sodium dihydrogen phosphate (D).

<(F)-1> Maleic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.)

<(F)-2>Succinic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.)

[phosphoric acid compound (G)]

In Comparative Examples 6 to 7, the following phosphoric acid compound (G) was used instead of phosphoric acid and/or sodium dihydrogen phosphate (D).

<(G)-1> Mixture of octadecyl dihydrogen phosphate and di-octadecyl phosphate (made by Asahi Kasei Kogyo Co., Ltd., "ADK STAB AX-71")

<(G)-2> Trisodium phosphate (manufactured by Miyama Chemical Co., Ltd.)

[Examples 1 to 17, Comparative Examples 1 to 9]

The raw materials including the components (parts by weight) described in Tables 1 and 2 were dry-mixed, and then a twin-screw extruder ("TEX-30" manufactured by Nippon Steel Works Co., Ltd.) having an extrusion temperature of 220 ° C was used. Melt kneading and granulation were carried out, and the obtained pellets were injected at a molding temperature of 220 ° C and a mold temperature of 60 ° C by using an injection molding machine ("IS55EPN injection molding machine" manufactured by Toshiba Machine Co., Ltd.). Forming, various characteristics were evaluated for the obtained test piece. The evaluation results are shown individually in Tables 1 and 2. As can be seen from the results of Examples 1 to 17, the present invention The thermoplastic resin composition of the present invention is excellent in mechanical properties or thermal stability which is excellent in impact resistance, no irritating odor during melt compounding and molding, and the safety of the thermoplastic resin composition from the start of production to the final product after forming. The sanitary surface is also excellent.

[Examples 18 to 20]

For the compositions of Examples 9, 10, and 12, after the components other than the aliphatic polyester resin (C) were dry-mixed, a twin-screw extruder (manufactured by Nippon Steel Works Co., Ltd.) set to a press temperature of 220 ° C was used. -30") After the melt-kneading, the aliphatic polyester resin (C) is supplied from the side inlet of the extruder, and further melt-kneaded and granulated by using an injection molding machine (manufactured by Toshiba Machine Co., Ltd.) "IS55EPN injection molding machine") The obtained pellets were injection-molded at a molding temperature of 220 ° C and a mold temperature of 60 ° C, and various characteristics were evaluated for the obtained test pieces. The evaluation results are shown in Table 1. The thermal stability or the impact resistance of Examples 18 to 20 have the same properties as those of Examples 9, 10 and 12, and in the surface appearance (sheet evaluation) and Examples 9 and 10. And 12 comparisons gave better results.

Industrial availability

The thermoplastic resin composition of the present invention is excellent in impact resistance, thermal stability, and further moldability, and is a film, a sheet, and a fiber. Cloth, non-woven fabric, injection molded product, extrusion molded product, vacuum pressure molded product, blow molded product, or composite with other materials, etc. With materials, motors. Materials for electronic equipment, agricultural materials, horticultural materials, fishery materials, civil engineering. Building materials, stationery, medical supplies, toilet seats, groceries, or other uses.

Claims (8)

A thermoplastic resin composition which is based on 10 to 80 parts by weight of the styrene resin (A), 5 to 70 parts by weight of the graft copolymer (B), and 1 to 85 parts by weight of the aliphatic polyester resin. (C) and 0 to 30 parts by weight of the resin composition of the acrylic resin (E) are formed by blending 0.1 to 5 parts by weight of phosphoric acid and/or sodium monosodium phosphate (D) in an amount of 100 parts by weight. The thermoplastic resin composition of claim 1, wherein the aliphatic polyester resin (C) is polylactic acid. The thermoplastic resin composition of the first aspect of the invention, wherein the styrene resin (A) is formed by polymerizing at least an aromatic vinyl monomer (a1). The thermoplastic resin composition of claim 1, wherein the graft copolymer (B) is graft-polymerized in the rubbery polymer (r) and contains at least an unsaturated alkyl carboxylate monomer (b1). It is formed by a monomer component. The thermoplastic resin composition of claim 1, wherein the acrylic resin (E) is a polymethyl methacrylate resin. A method for producing a thermoplastic resin composition, which is a method for producing a thermoplastic resin composition according to any one of claims 1 to 5, which is characterized in that, other than the melt-kneading of the aliphatic polyester resin (C) After the component, the aliphatic polyester resin (C) is further added and further melt-kneaded. A molded article formed by molding a thermoplastic resin composition as disclosed in claims 1 to 5. A sheet formed by molding a thermoplastic resin composition as disclosed in claims 1 to 5.